Dirac Reviews

[Snarfie]

As far as I know, REW only allows you to create all-pass filters with "falling" phase, which are not suitable for counteracting the crossover-related phase wrap. So I guess rePhase would be the better tool to use for this purpose.

To get a "perfect" looking impulse and step responses you need to correct the excess phase which is introduced by the crossover, which in turn aligns the tweeter and woofer responses.

E.g. here's a comparison of the impulse and step responses of the original measurement, vs the minimum-phase version of the same magnitude response:View attachment 384729View attachment 384730

So if you're able to calculate a filter that counteracts the crossover-related excess phase part of the response you will get the nice-looking impulse/step responses you are after.

The way I tried to do it:

1. Open a measurement in REW and apply some (strong) smoothing to the frequency response. I used "1/1 smoothing" in my test.
2. Click "Actions" > "Estimate IR Delay" and then shift the IR accordingly -> this will remove the phase wraps introduced by the delay of the measurement system, including the delay introduced by propagation of sound through air (from speaker to mic).
3. Click "All SPL" view, then go to "Actions" > "Measurement actions" > "Excess Phase Version" -> this will create a new measurement with flat magnitude response and only the excess phase component of the original measurement
4. Export the previously generated 1/1 smoothed Excess Phase measurement and import into rePhase.
5. In rePhase we're aiming to get the phase close to zero in the mid and high frequencies. It seems to me that aiming for flat phase between 1kHz and 10kHz gives pretty good results for this purpose. Use the "Filters Linearization" view and add a filter to counteract the crossover phase wraps, and then add a few "Paragraphic Phase EQ" filters to tune as needed. My Revel M16 is specified with a crossover at 2100Hz, so I used that with a "LR 24 db/oct" crossover preset in "linearize" mode and then added just 4 paragraphic phase filters with relatively low Q values (0,5 or 1).
   This was the result:View attachment 384852
6. Export the phase correction with the appropriate number of taps and sampling frequency (I used 2048 taps and 48kHz).

In my case, here's how this manual phase correction compares to Dirac (and original measurement without any correction):
View attachment 384853
View attachment 384854

So it is possible to get similar-looking impulse/step responses as with Dirac, but it might require a bit of experimentation with smoothing and choosing the frequency range where you apply the correction.

Just to note that if you overdo phase correction you can get audible artefacts like pre-ringing and such. Probably you also need to be careful about filter stability. I don't have too much experience with this kind of correction so I'll leave it to other members to chime in. Hope this helps!

This comes close to attend university classes

 

[ah-ra]

This comes close to attend university classes

Yes...you might get a Ph.D. in DSP....

 

[ah-ra]

I got the impression that most people always like what the have (including me ). They think that their home perceived sound is quite good. 99.9% never enterd a professional studio controll room ( besides probably some proffesional ASR members) from at least let say 1 million euro or dollar with a investment ratio of 70/30 which relate to 70% room treathment an 30% gear. On top of that most could probably not distinguished the difference between instruments (so how they must sound on a recording) like a Bösendorfer or Steinway piano's a Telecaster or a Stratocaster an so on.

Than we have seperation between instrument an voices in a well recorded session including the reverb time from the venu. In suche quality recording using the needed an correct placed quality mic's it contain the information for staging imaging for instance. I noticed (in my current mancave) that most of this is revealed with (a well measured) Room correction (DSP) if your room like mine has a horrible acoustic. I guess that 90 % has the same problem. So get acainted with the correct sound which means if you listen to a bad recording the DSP will reveal that without mercy (which means DSP does it job) if it is well recorded you could be in heaven with DSP. If you have a well treathed listening room you don't need DSP so atleast do a Propper measurment with REW for instance it reveal a lot. I use Mathaudio room EQ did compare it with Lyngdorf an Dirac quite similar sound/result all of them i noticed. DSP for me did let me rediscover my music collection.

From my experience, at home you get the best results with some physical room treatment in combination with DSP... A DSP alone cannot correct everything your room does to the signal. Physical treatment will allow your DSP to function even better and you will need less filter which will most probably add to the sound.

 

[Sal1950]

A / B

Moving from an early version of Audyssey XT32, Bass tightened up (marginal), midrange, vocals, dialogue became distinctly clearer, imaging improved marginally...

The old version of XT32, had no way to turn off the MRC (mid range compensation)... so it is possible that a current D&M implementation would provide the same benefits.

Be that as it may - Dirac has proven itself a worthwhile upgrade, and resulted in my setup sounding better than it ever has (not just in movie mode, but also in stereo, music mode)

Dirac is an excellent DRC system no doubt, but is also quite costly.
Included with most D-M processors, XT32 is FREE.
The $20 Editor app will allow you to turn off MRC, make individual curve corrections, and more. A real steal in DRC.
The $200 Audyssey MultiEQ-X is a highly configurable excellent PC based application and is capable of doing just about
everything the Dirac Live system can with probably equally excellent final results.
Both Dirac and X require a lot more hands-on work with fairly steep learning curves for the perfectionist.
A full boat Dirac upgrade in a D-M processor will set you back around $700.
It's all about the money and the effort you want to put in that will determine the end results.

 

[Heyu]

A+
For me Dirac is a learning curb. I had a hard time getting the levels right especially the subs until I finally got it right. I recently got DLBC and can say it really made a difference in my bass compared to standard Dirac. Without bass control I had to raise the trim or gain afterwards. Now, at the same time my bass was likely not neutered this time because I got the levels right pre calibration. For example before the subs were -14.5 and -8 and now -5 and -3 or so. So it is hard to say if DLBC had a hand in this but I am loving my bass.

 

[alvigg]

Agree that Dirac Live Bass Control takes time. Because of it, I upgraded to 4 subs and the bass in the sweet spot is excellent (3 measurement positions) with other spots very bassy. My 9 position measurement solved the over bassed spots but the sweet spot was not as good.

 

[Kal Rubinson]

For me Dirac is a learning curb.

Some people do think that way.

 

[IMWorks]

"A" rating for me. Soundstage is wider. In-room response curve is more level across all frequencies. More detail across the board and better base control, despite having pre-calibrated my subwoofer with its mic kit and software interface prior to using Dirac Live. Down-rated to a flat "A" rating due to using the "Direct Live Processor" version in tandem with JRiver Media Center and I then get distortion when minimizing the "Direct Live Processor" window while in playback mode. Minor inconvenience and I've written Dirac for their feedback.

 

[Snarfie]

Dirac is an excellent DRC system no doubt, but is also quite costly.
Included with most D-M processors, XT32 is FREE.
The $20 Editor app will allow you to turn off MRC, make individual curve corrections, and more. A real steal in DRC.
The $200 Audyssey MultiEQ-X is a highly configurable excellent PC based application and is capable of doing just about
everything the Dirac Live system can with probably equally excellent final results.
Both Dirac and X require a lot more hands-on work with fairly steep learning curves for the perfectionist.
A full boat Dirac upgrade in a D-M processor will set you back around $700.
It's all about the money and the effort you want to put in that will determine the end results.

Probably i missed it but do you use DSP for room correction if so what are you using.

 

[Zapuan]

A is my rating